Least Common Multiple

Least Common Multiple: Learn

The Least Common Multiple (LCM) is the smallest number that two or more numbers will divide into evenly.

For a single number it is easy to find multiples by simply
multiplying the number by increasing whole numbers
(or, more simply "counting by" that number).

Example: multiples of 4 are 4, 8, 12, 16, 20, 24, and so on.

There are two good ways to find the Least Common Multiple of two numbers.
Here's the first way:

Find the Greatest Common Factor (GCF) of the numbers

Multiply the numbers together

Divide the product of the numbers by the GCF.

An an example of this method, consider the numbers 15 and 12.
Their GCF is 3, so the LCM is 15*12÷3 = 180÷3 = 60.

Alternatively, you could begin counting by the larger number
until you reach a multiple which is also a multiple of the smaller number.

For example, again consider 15 and 12. Fifteen is the larger number, so
start counting by fifteens:
15 - no, not a multiple of 12
30 - no, not a multiple of 12
45 - no, not a multiple of 12
60 - yes, 12*5=60 so 60 is the LCM.